A wearable muscular power assist robot must lift and transfer an object while moving depending on a wearing user's intention. When the robot lifts a heavy object, the force of the wearing user is transferred to the robot, and the force transferred to the robot is amplified, thus enabling the robot to lift the heavy object. The present invention relates to a method of performing control so that a wearing user can always lift objects having various weights with a constant force regardless of a variation in the weight of an object to be lifted.
An existing wearable muscular power assist robot is configured such that an electromyogram (EMG) sensor is attached to the body of a wearing user, and has been used to determine the motion intention signal of the wearing user using the contraction and relaxation of a muscle, send the signal to a robot controller and then drive an actuator. However, such a robot is disadvantageous in that when the wearing user moves, a phenomenon frequently occurs in which the EMG sensor is not closely attached in an exact location to the body of the user, with the result that the motion intention signal of the wearing user is distorted.
Further, the robot is disadvantageous in that the operation of the robot reacts sensitively to a variation in the weight of an object to be lifted.
Therefore, there is a need to implement such a control system using only a force sensor so as to guarantee the precision of sensing and precisely control the robot based on sensing. An attachment-type EMG sensor is considerably inaccurate in a certain aspect and is expensive, thereby making it difficult to commercialize.
As a result, technology is required that allows a wearing user to feel the same load even when he or she lifts objects having any weight, by precisely measuring a required force using a force sensor and by easily controlling a lifting operation based on the required force, thus reducing a burden on the body of the wearing user.
The foregoing is intended merely to aid in the better understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.